Everything else in the fall garden is winding down. Garlic is the one crop that starts now. One clove goes in as the leaves come down; a whole head comes up next June. It's about the easiest crop a beginner can grow, if you get three things right: when, which kind, and how deep.
When: cool soil, not a calendar date
The goal is simple. You want the clove to grow roots before winter, but not much top growth. Plant too early, while the soil is still warm, and it pushes up leaves that winter burns back. That's why we said in What You Can Still Plant This Fall that garlic isn't late in September, it's early.
Extension services put that moment a few different ways, and they all land in the same place. South Dakota State says to wait until the soil has cooled, with 50°F at four inches deep as the ideal. Minnesota says to plant one or two weeks after the first killing frost. Cornell says three to four weeks before the ground freezes. A cheap soil thermometer settles it.
In the mid-South the ground rarely freezes solid, so the soil-temperature rule is the one to go by. UT Extension gives East Tennessee a window from September 1 to November 1 and West Tennessee September 15 to November 15. In our own Middle Tennessee garden, where the first frost comes around November 3, we aim for mid-October to early November, well inside both windows and after the soil has cooled. Farther north, move it earlier. Farther south, later. Your local planting calendar shows your frost date to count from.
Which kind: hardneck or softneck
Hardneck garlic sends up a flower stalk called a scape and generally handles cold best. Softneck garlic doesn't flower, stores longer, and handles warm winters better. It's also the type you usually find in the grocery store. Minnesota tells northern growers to use varieties adapted to cold climates. Clemson says Rocambole hardnecks don't do well in South Carolina's warm climate and recommends Creole types for the South. Tennessee sits in between, and UT notes that gardeners here can grow either one. Can't decide? Plant a few of each.
Don't plant the grocery-store garlic
It's tempting, and it rarely works well. Iowa State Extension gives two reasons. Most store garlic is treated to keep it from sprouting, and treated cloves often rot before they grow. It's also usually softneck garlic from a warmer region than yours. Maryland and South Dakota State add a third reason: it can carry disease without showing any symptoms, and you don't want that in your soil. Buy certified disease-free seed garlic from a garden center, a seed company or a local grower. Then do the one thing that matters most: plant only the biggest cloves. UT, Clemson and Oregon State all say the same thing. Bigger cloves grow bigger bulbs. Cook with the small ones.
Depth, spacing and soil
Split the head just before planting, skins on. Set each clove pointed end up, flat root end down. Cloves planted sideways grow crooked necks. For depth, cover each clove with about 1 to 2 inches of soil: UT says 1 to 1½ inches, Maryland up to 2. In really cold country, plant a bit deeper: Minnesota places the base of the clove 2 to 3 inches down. Space cloves about 4 to 6 inches apart, with rows 12 to 18 inches apart, or use a 4-by-4-inch grid in a raised bed, as UT suggests.
Garlic likes loose, well-drained soil with plenty of organic matter. It wants a slightly acidic to neutral pH: UT suggests 5.8 to 6.5, Minnesota 6.0 to 7.0. A soil test beats guessing. UT recommends a complete fertilizer at planting, then more nitrogen in spring once the plants are about 6 inches tall.
Mulch, then leave it alone
After planting, mulch with straw or shredded leaves. It keeps weeds down and keeps the soil temperature from swinging. The amount depends on your winter. Minnesota uses 3 to 4 inches, Cornell 4 to 6, and South Dakota State adds 6 to 8 inches after the soil freezes to keep the cloves from heaving out of the ground. Clemson still calls for 4 to 6 inches of weed-free straw in late fall in South Carolina. In the North, pull it back in spring once hard freezes are over. After that it's just weeding and watering.
Scapes, harvest and curing
In late spring, hardneck garlic sends up a curling scape. Snap it off after the first curl. This puts the plant's energy into the bulb, and scapes are good to eat. You can use them like green onions.
Harvest time is about counting leaves. UT Extension says garlic is close to ready when it has four to six green leaves left. Minnesota's version is to start when the lower leaves have turned brown and about half the upper leaves are still green. Softnecks often tell you themselves when the tops flop over at the neck. Don't wait until every leaf is brown. Lift the bulbs gently with a garden fork.
Then cure them with the tops still on somewhere shady, dry and airy for two to four weeks, until the necks are dry and the skins feel papery. Then trim, and save your biggest heads: they're next fall's seed garlic.
Where the moon fits
Traditionally, garlic is a waning-moon job. The waning fortnight, from a full moon to the next new moon, is the "downward" half of the month: roots, bulbs and soil. We'll be straight about it, as always. When Illinois Extension reviewed the research, it found no consistent relationship supporting a lunar influence on plant life. The moon gives you a rhythm. It doesn't make garlic grow better. The soil temperature still decides the week, and the moon just helps you pick a day within it.
Here are the fall 2026 waning windows in US Central time:
September 26 to October 10. Full moon September 26 at 11:49 a.m. CDT, new moon October 10 at 10:50 a.m. CDT. This one suits gardens in the far north where the soil is already cool. For most of us it's too early.
October 25 to November 9. Full moon Sunday, October 25 at 11:12 p.m. CDT, new moon Monday, November 9 at 1:02 a.m. CST. Clocks fall back on November 1 in between. This is the mid-South window. In practice that's October 26 through November 8, which fits Middle Tennessee's timing exactly.
November 24 to December 8. Full moon November 24 at 8:53 a.m. CST, new moon December 8 at 6:52 p.m. CST. Use it only if your ground can still be worked and it falls within your own extension office's planting window.
Sources: UT Extension D 75, "Garlic for the Tennessee Vegetable Garden" · UT Gardens, "The Most Wonderful Time of the Year: Garlic" · University of Minnesota Extension, "Growing Garlic" · Cornell Cooperative Extension Monroe County, "Growing Garlic" · University of Maryland Extension, "Growing Garlic in a Home Garden" · Clemson HGIC, "Onion, Leek, Shallot & Garlic" · SDSU Extension, "Planting Garlic" · Iowa State Extension, "Can I plant garlic cloves from the grocery store?" · Oregon State University, "Get your garlic on" · University of Illinois Extension, "Lunar Influence on Gardening" · U.S. Naval Observatory, Phases of the Moon